The ruling party is running a campaign to criticize the opposition.

Literal

Ruling-party [topic-は] opposition-party criticism [possessive-の] campaign [object-を] is-unfolding.

与党 ('ruling party') and 野党 ('opposition party') are core Japanese political vocabulary. 非難 ('criticism / denunciation'). 展開する ('unfold / develop / deploy'), often used for strategies, campaigns, and narratives. Political news register.